New Flashcards
What is a monomer?
A smaller, repeating molecule from which larger polymers are made
What is a polymer?
A larger molecule which is made up of identical repeating monomers.
What is a condensation reaction?
A reaction in which two molecules join together, forming a covalent bond and releasing a molecule of water.
What is a hydrolysis reaction?
A reaction in which the covalent bond between two molecules is broken, which uses up a molecule of water.
Which polymer consists of repeating nucleotides?
Polynucleotides (DNA or RNA)
Which polymer consists of repeating monosaccharides?
Polysaccharides
Which polymer consists of repeating amino acids?
Polypeptides (Proteins)
What is the difference between alpha and beta glucose?
In α-glucose, the H is above the OH whereas in β-glucose, the OH is above the H
Draw a molecule of alpha glucose.
https://static.aqa.org.uk/assets/image/0018/235440/00055366-DA00046397-DB.png
Draw a molecule of beta glucose
https://static.aqa.org.uk/assets/image/0008/235439/00055366-DA00046396-DB.png
What are isomers?
Molecules with the same molecular formula but differently arranged atoms.
What are disaccharides and how are they formed?
A disaccharide is two monosaccharides joined together with a glycosidic bond. They are formed by a condensation reaction, which releases a molecule of water.
Which disaccharide does Glucose and Glucose make?
Maltose
Which monosaccharides make Maltose?
Glucose and Glucose
Which disaccharide does Glucose and Fructose make?
Sucrose
Which monosaccharides make Sucrose?
Glucose and Fructose
Which disaccharide does Glucose and Galactose make?
Lactose
Which monosaccharides make Lactose?
Glucose and Galactose
What are polysaccharides and how are they formed?
Polysaccharides are made up of many (more than 2) monosaccharides, joined together with glycosidic bonds. They are formed by many condensation reactions, releasing water molecules.
Describe the basic function and structure of starch.
Starch acts as an energy source in plant cells. It is a polysaccharide of alpha glucose. It contains both Amylose and Amylopectin. Amylose has 1-4 glycosidic bonds and is therefore unbranched. Amylopectin has both 1-4 and 1-6 glycosidic bonds, meaning that it is branched.
Describe the basic function and structure of glycogen.
Glycogen acts as an energy store in animal cells. It is a polysaccharide of alpha glucose. It has both 1-4 and 1-6 glycosidic bonds. Therefore, it is branched.
Describe the basic function and structure of cellulose.
Cellulose acts as structural support in plant cells. It is found in the cell walls of plant cells. It is a polysaccharide of beta glucose, held together by 1-4 glycosidic bonds forming straight unbranched chains. Chains are joined together with hydrogen bonds forming microfibrils.
Explain how the structure of starch is related to its function.
Starch is helical, so it is compact for storage in cell. Also, it is a large molecule, meaning it can not leave the cell. It is also insoluble in water, meaning that it does not affect the water potential of the cell, so no osmotic action which could damage the cell occurs. Also, it is branched to increase the surface area for faster hydrolysis.
Explain how the structure of glycogen is related to its function.
Glycogen is branched are is therefore compact and more molecules can fit in small area. Also, the branching results in a larger surface area for the enzymes to quickly hydrolyse the glycosidic bonds to release glucose. Also, it is a large molecule meaning it can not leave the cell. It is also insoluble in water, meaning that it does not affect the water potential of the cell, so no osmotic action which could damage the cell occurs